TW201219864A - Optical sheet having thin double-sided light guide plate - Google Patents

Abstract

The present invention provides an optical sheet having a plurality of light guide plate patterns, each light guide plate pattern having a micro-patterned output surface for emitting light, and a micro-patterned bottom surface opposing to the output surface, made in steps comprising: extruding a first resin into the nip between a first pressure roller and a first patterned roller to form a first layer at a first patterned roller surface temperature T1 and a first nip pressure P1, the first layer having an unpatterned surface and a patterned surface, the patterned surface having a micro-pattern transferred from the first patterned roller, and conveying the first layer into a nip between a second patterned roller and a second pressure roller in a second extrusion station; and extruding a second resin into the nip between the second pressure roller and the second patterned roller and onto the unpatterned surface of the first layer to form a second layer at a second patterned roller surface temperature T2 and a second nip pressure P2, the second layer having a micro-pattern transferred from the second patterned roller; the combined first and second layers forming the optical sheet comprising the plurality of light guide plate patterns.

Description

201219864 VI. Description of the Invention: [Technical Field] The present invention relates generally to an optical sheet, and more particularly to 'related to an optical sheet having a double-sided light guide plate, and manufacturing the same The method of sheeting. [Prior Art] Liquid crystal displays (LCDs) have continued to increase in price and performance, and have become the preferred display technology for many computers, instruments, and entertainment devices. Typical LCD mobile phones, notebook computers, and screens include light guides that receive light from a light source and distribute the light more or less evenly throughout the LCD. At present, the thickness of the light guide plate is typically between mm8 mm and 2 mm. The light guide must be thick enough to effectively couple the light source (typically a CCFL or multiple LEDs) and redirect the light to the viewer. Meanwhile, it is generally difficult and expensive to manufacture a light guide plate having a thickness of less than about 0.8 mm and a width or length of more than 60 mm by a conventional injection molding method. On the other hand, it is generally desirable to thin the light guide plate to reduce the overall thickness and weight of the LCD, especially when the LED size is reduced. Therefore, in order to achieve optimal light utilization efficiency, low manufacturing cost, thinness and brightness, a balance must be struck between these conflicting requirements. In most applications, the light guide must have a pattern on one side ("single side light guide") to achieve adequate light extraction and reorientation. However, in some cases, such as a turning film system, it may be desirable to have a micropattern ("double side light guide") on both sides of the panel. The use of a transfer film in an LCD backlight unit has been shown to reduce the amount of light management required to achieve a sufficiently high amount of illumination.

S 201219864 (1 ight management fi lm) number. Unfortunately, when the plate is relatively thin (< 0.8 mm), achieving a good copy of both patterns is a major obstacle to the acceptability of the turning film. In fact, the choice of manufacturing methods for thin double-sided light guides is critical in controlling price, productivity and quality, making turning film technology more attractive. The choice of this method to date has been an injection molding method and some variations thereof. In this method, the hot polymer melt is sprayed at a high speed and high pressure into a mold space having a micromachined surface (with a pattern) which is transferred to the surface of the cured formed sheet during the forming and cooling stages. The injection molding technique is quite effective when the plate thickness is relatively large by 0.8 mm) and the lateral dimension (width and/or length) is relatively small by 300 mm. However, in the case of a relatively thin plate with a micropattern of relatively thin «0. 8 mm), the injection molding method requires a significantly higher injection pressure, which typically results in poor replication and high residuals on the forming plate. Stress and birefringence can result in poor dimensional stability and low yield. Another method for fabricating a single-sided light guide plate (with a micropattern on a surface) is to print a discrete micropattern on a flat broadcast using inkjet printing, screen printing or other printing methods. One side of the cast sheet is on the side. A disadvantage of this method is that the extrusion casting step requires an expensive additional printing step, the shape and size of the discontinuous micro-extractor being predetermined and not well controlled. This approach becomes less attractive when both surfaces need to be patterned, as required by the present invention. The continuous, roller-to-roller extrusion casting process is well suited for the manufacture of thin, one-sided micropatterned films, such as U.S. Patent No. 5,885,490 (Kawaguchi et al. 5, 95, 2012, 1986, 1984); U.S. Patent Publication No. 2007/0052118 A1 (Kudo et al.), U.S. Patent No. 2007/0013100 to AK Capaldo et al., and U.S. Patent No. 2008/0122135 (Hisanori et al.). Kawaguchi et al. consider applying a pattern onto the patterned side of a flexible carrier film that passes through the nip zone between two opposing rotating rollers to apply a pattern to both sides of the product film. The possibility. This method was originally expensive, because the surface used for patterning itself is a film that must be separately prepared before the casting step and discarded after very limited use. Capaldo et al. disclose an extrusion casting process for making a film having a controlled sugar content on a surface. Hisanori et al. and Kudo et al. also disclose film patterning methods using extrusion casting, but they limit their disclosure to single-sided films. Kudo et al. specifically point out the need for a patterned roller having a relatively high surface temperature (> Tg + 20 ° C). Takada et al. disclose a method of making thick light guides using extrusion casting (W0 2006/098479), but this method is also limited to the manufacture of single-sided light guides. Thus, while there have been solutions to specific light guide plates and methods of making such plates by, for example, extrusion, roller-to-roller operation, there is still a need for economical fabrication using a single pass extrusion casting process as disclosed herein. A method of a double-sided light guide plate of the kind. SUMMARY OF THE INVENTION The present invention provides an optical sheet having a plurality of light guide plate patterns each having an input surface for receiving light from a light source, and a micropatterned output for illumination (for emitting 1 ight) a surface, and a micropatterned bottom surface opposite the output surface. The optical thin 6 95329

S 201219864 • The film is manufactured by extruding the first resin into the cooling gap between the first pressure roller and the first patterned roller, and forming the first patterned roller surface temperature ^' and the first slit pressure P1. a first layer having an unpatterned surface - φ and a patterned surface - the patterned surface having a micropattern transferred from the first patterned roller and transferring the first layer to a second extrusion The gap between the second patterned roller and the second pressure roller in the station. The optical sheet is further fabricated by extruding a second resin into a nip between the second pressure roller and the second patterned roller and extruding onto the unpatterned surface of the first layer and at a second The patterned roller surface temperature T2 and the second nip pressure Ρ2 form a second layer 'the second layer has a micropattern transferred from the second patterned roller; the combined first layer and the second layer form a plurality of light guiding plates An optical sheet of the pattern. [Embodiment] The light guide plate of the present invention uses light redirecting. The price is as follows: the microstructure is formed into a crucible, placed on the surface of the light guide plate, and the light extraction microstructure (the continuous component of the sweater) , placed on the opposite surface of the light guide plate). The real 稜鏡 has at least two flat faces. However, since the light redirects - or the surfaces are not necessarily flat in all embodiments, but may be curved or have a plurality of segments (Μ-), more in this month - The general name is "light redirect structure." Large optical sheet having a plurality of light guide plate patterns Fig. 1 is a top plan view of the optical sheet 3 of the present invention. When the length of the heart is greater than or equal to 01, more preferably greater than or equal to (10), especially preferably greater than or equal to the heart, and its width A% A is equal to or equal to 0·3π], more preferably greater than or equal to 95§19 7 201219864 〇. When =1 is more preferably greater than or equal to 0.9 m, the optical sheet 300 is referred to as large. The light-dried sheet 300 has a thickness ranging from about 〇5 mm to about 2 mm, more preferably ranging from about 〇.lmm to about 〇7 mm, and particularly preferably ranging from about 〇.2 coffee to about 〇. 5 coffee. The optical sheet 3 has at least two light guiding plate patterns thereon, more preferably at least four light guiding plate patterns thereon, and particularly preferably at least 20 light guiding plate patterns thereon. The optical sheet 300 shown in Fig. 1 has light guide plate patterns 25{^ to 250j, each of which also has a length and a width. For example, the light guiding plate pattern 25A has a length 厶 and a width 趴, and the light guiding plate pattern 25〇6 has a length 见 and a viewing angle. Each of the light guide plate patterns also has a wheel entry surface 18, a terminal surface 14, and two side surfaces 15a, 15b. The advantage of having a plurality of light guide plate patterns on the same optical sheet is to increase productivity and reduce the cost per sheet of light guide. If the light guide plate pattern is not rectangular, its width and length are defined as the largest dimension in the two orthogonal directions. The light guide plates cut by the large optical sheets 2A and 2B are a bottom view and a side view, respectively, of the light guide plate 250 cut by the large optical sheet 3 of Fig. 1. The light guiding plate 250 may be any one of the light guiding plates 250a to 250j in Fig. 1. Has a length z and a width 酽. When used in an LCD backlight unit, the light guide is always coupled to one or more light sources 12. The width 妒 is defined as being parallel to the source ι2 aligned along the gamma direction, and the length Z is defined to be perpendicular to the width 妒 or γ direction. The length 妒 and the width 妒 are generally varied between 20 mm and 500 mm. Depending on the application, the thickness a of the light guide plate 250 is generally uniform (unif 〇 rm), that is, the thickness variation is usually less than 20%, more preferably less than 10%. More preferably less than 8 95329 201219864 5% ° The light guide plate 250 has a micropattern 217 of discontinuous elements, the discontinuous elements being indicated by small dots on the bottom surface 17. The pattern 217 has a length 厶 and a width, respectively parallel and perpendicular to the light source 12. In general, the pattern 217 has a smaller size than the light guide plate 250 in the length direction, the width direction, or both directions. That is, the size and number of Zfl Hong and milk discontinuous elements vary along the length and width directions. The two-dimensional (2D) density function of the discontinuous element at the position (especially;;) is (Xy), which is the total area of the discontinuous elements divided by the discontinuous element = total area where m is produced. Especially, r is a discontinuous component. The distance from the origin α is along the length and width directions. For the sake of convenience, the point 〇 is selected to be located near the input surface 18 of the light guide plate 25 角 = angle. In the example shown in Fig. 2C, the six discontinuous elements 227 each have an area called - (iv) which is still "in a rectangle having a small area." In this small area, the density of the discontinuous elements is !>,·/(Δ% ·μ.) "3 , where Ν=6, which represents a small area Δρ·ΔΖ. The total number of consecutive το pieces. The discontinuous elements in this area may have the same generality. The density of the discontinuous elements will vary with position (4). In fact, the density function Mb changes very little in the width direction, but in the length direction. Changed a lot. In short, the one-dimensional production function is (1) usually used to describe the characteristics of the pattern of discontinuous elements, and ^ is the same as = s妒 (4), (10). One of the other forms of dimension 201219864 (ID) density function can also be easily derived from the 2D density function. In the following description, the independent variable x is applied to explain any of the one-dimensional density functions /) 可) that can be used to calculate. For example, χ can be a radius calculated from the origin, if the light source is point-like and located near the corner of the light guide plate. As shown in FIG. 2, the light guide plate 250 has a light input surface 18 for coupling light emitted by the light source 12, and an output surface ι6 for emitting light from the light guide plate 250, the terminal surface 14 being located opposite the input surface 18, The bottom surface 17' is located opposite the wheeled surface 16, and the two side surfaces 15&, 15b. Light source 12 can be a single linear source such as a cold cathode fluorescent tube (CCFL) or a plurality of point sources such as light emitting diodes (LEDs). Alternatively, pattern 217 can be located on output surface 16 of light guide plate 25A. Fig. 3A is a view of the light guide plate 250, the ruthenium film such as the turning film 22, and the enlarged side view of the reflective film 142 in a direction parallel to the width. There are a plurality of turns 216 on the output surface 16 of the light guide plate 250 and a plurality of discontinuous elements 227 on the bottom surface π. Fig. 3B is a side view of the light guiding plate 250 viewed along the length direction. The crucible 216 located on the output surface 16 generally has an apex angle α〇.稜鏡 can have a rounded top. Figure 3C is a top view of prism 216. In this example, 稜鏡 are parallel to each other. In another example, as shown in Fig. 3D, the crucible 216 is curved and wavy. Any of the known modifications can be used in the present invention. Examples include prisms with variable height, variable apex angle and variable pitch. Figures 4A-1, 4A-2 and 4A-3 show perspective, top and side views, respectively, of a first type of discontinuous element 227a that can be used in the present invention. Each non-contiguous element is essentially a triangular segmented rib

10 95329 S 201219864 Mirror. The fourth (4), 4?-2 and 4B-3 figures show perspective, top and side views, respectively, of the discontinuous element 227b of the first type that can be used in the present invention. Each of the non-continuous elements is a substantially triangular block type 平面 4CM, 402 and 4 (2) having a plane (4), and a perspective, top view and a side view of the third discontinuous element 227c for the fourth (4). Each _ discontinuous element is a substantially circular segmental ritual. Other discontinuous elements of known shape 0 cylindrical and semi-circular, can also be used. They can be symmetrical or asymmetrical. The above examples are non-exclusive and other forms of elements may also be used in the present invention. A discontinuous element having the above shape is generally known, and the second T-sheet is relatively shallow and has the following key features: its dimension d is smaller than the length ^ and width. More specifically, the height d is preferably less than or equal to 12_, more preferably less than or equal to · m, particularly preferably = or equal to 1 money ^ and the width ^ is more than ... m, more preferably greater than or equal to the heart m, especially Good is greater than or equal to the claws. In general, the length and width ^ are less than 1〇〇_. Alternatively, the ratio neon is preferably less than or equal to 〇 45, more preferably less than or equal to 0.3', and particularly preferably less than or equal to 〇 2. The discontinuous element containing = has some advantages, and the process of the following 3 optical sheets of the non-L piece can be easily fabricated on the patterned roller. Usually one-dimensional work:: = wide roller off discrete components with the above characteristics, / and: = tool wear situation. Secondly, the pattern formed by the discontinuous transition, the sheet Γ = low temperature, is easily transferred from the patterned roller to the optical fidelity of 'd'. Third, since only a slight wear of 95329 11 201219864 is encountered, the pattern formed by the discontinuous elements has a long life. Finally, a light guide having such a pattern does not easily wear adjacent elements in the backlight module. These advantages are more pronounced when making large optical sheets in the following discussion. In the comparative example, the discontinuous member has a length ΔZiO/zm, a width Δ ^50/zm, and a height d = 25/zm, and thus does not have the dimensional characteristics of the present invention. In general, the roller is 0. 8m wide and has a radius of 0. 23m. Since the ratio of d/ΔΖ to d/Δ F is large, the diamond tool is easily broken, and the pattern having the discontinuous element is difficult to manufacture on the patterned roller. Moreover, in the preferred method embodiments discussed below, the pattern having such discontinuous elements cannot be easily transferred from the patterning roller to the optical sheet 300. In addition, the pattern with this discontinuous element cannot be used many times before the pattern is deformed or shattered. Finally, a light guide plate with this pattern may wear adjacent components. Method for manufacturing a double-sided optical sheet and a light guide plate In one method, a method for manufacturing a double-sided light guide plate comprises the following three key steps: 1. preparing two patterned rollers; 2. using the two patterned rollers, via An extensive optical sheet comprising a plurality of light guide plate patterns is produced by extrusion casting; and 3. The large optical sheet is cut into a plurality of double side light guide plates having a specific length and width. These steps are described below. Preparation of Patterned Rollers Referring to Figures 5A and 5B, a pattern 252 comprising a plurality of sub-patterns 252a through 252d is fabricated on patterned roller 480a by direct micromachining using, for example, a suitable diamond tool. Figure 5A is a pattern 12 95329

S 201219864 The front view of the scroll wheel 480a is patterned 252a, 252b, the radius of the roller is 10,000, and the width is the heart 1. Figure 5B is a schematic illustration of an unrolled pattern 252 comprising four sub-patterns 252a through 252d. Pattern 252 has a length of 1, and one. The secondary pattern 252a has a width %1 and a length In. The four sub-patterns may have the same or different widths or lengths. In one example, i?i»152imn, i^i=2; ri?i®955mm, ^1=406111111, 1^=182111111, and ^^39601111. Typically, there is a blank space between two adjacent sub-patterns. However, in some cases, the white space between two adjacent sub-patterns can be minimized to improve the utilization efficiency of the roller surface. In either case, the density function of each sub-pattern (as discussed earlier) may vary, both in length and/or width. In one example, the density function will decrease first and then increase. Similarly, another pattern 254 is fabricated on another patterned roller 480b and fabricated by known engraving. Figures 6A and 6B show a front view and an expanded view of the pattern 254 on the patterned roller 480b. The patterned roller 480b has a radius of 2, a length of 4?2 = 2?7?2, and a width of 2. Pattern 254 has a width of 2 and a length Ap2. In one example, and 2= and ιβ152ιηιη, Ακ2=Αρ2=2疋 and 2=955111111, heart ι=406ιμ, and fF^MOOnnn. The patterns 254 in the sixth and sixth views are linear patterns parallel to the length direction of the roller 480b. The linear pattern can be a known linear 稜鏡, lens or cylindrical pattern. It can have a variable or constant pitch, height or shape. In another example, the pattern 254 is disposed at an angle relative to the width of the roller 480b. In another example, the second pattern 254 is a wavy linear 稜鏡 pattern. In yet another example, the second pattern 254, like the 13th 95329 201219864 - pattern 252, contains a plurality of sub-graphs 254 with a smaller coverage (with roll, : column, second legend Wi. in - (four) f t The size is relatively small, that is, the pattern 254 has only a pattern of 2% to 252d, and the pattern is 255. The concentric case contains, for example, the %th image and the third 妒", the stencil, in which case the pattern 254 is a continuous pattern. However, the pattern 254 may also have a pattern similar to that. The sch. 兀忏 gentleman "made on the surface of the roller The sighs made by the secret casting method are used for the reverse of the pattern on the light guide plate ("negative type"). Another option to add (or impart) a micropattern to the surface of the roller involves patterning the roller or sleeve (which may be patterned carrier film 474a, see Figure 11A below) or pattern strips 479, 479a or 479b, which will be described in the following 12B to 12D drawings). The patterned sheet or sleeve can be a metal or polymer system. After the patterns 252 and 254 are fabricated on the patterned rollers 480a, 480b, respectively, in the form of optical sheets 300 of optical sheets 300a, 300b, 300c, 300d and 300e, they can be fabricated in one of several extrusion casting embodiments. 7A and 7B are top views of the optical sheet 300 having the pattern 252' on one side and the pattern 254 on the other side. Two light guide plates 250al and 250a2 having different sizes and blank spaces are called to be cut from the same pattern 252c. This flexibility, which varies in size of the light guide plate, can be achieved by the large optical sheet of the present invention. Extrusion Casting Method 95329 201219864 Preferably, the extrusion casting method of the present invention is schematically shown in Fig. 8A. The method comprises the steps of: (1) a polymer resin 450a having the desired physical and optical properties, extruded through a first extrusion station 470a having a first extruder 476a and a first extrusion die 477a to a hard On the flexible polymeric carrier film 474, the carrier film 474 is fed from the supply roller 472a into a first nip between the two oppositely rotating rollers 480a and 478a. As discussed earlier, the roller 480a is a patterned roller having a microfeature pattern 252 designed for the light guide of the present invention. The surface temperature TpaR! of the roller 48〇a is maintained such that T1>Tgl-5(rc, where Tgi is the glass transition temperature of the first extruded resin 45〇a. The roller 478a is the first pressure roller, which is soft^ (4) 'The table H degree Tp 1 < T1. The cooling pressure between the two rollers is maintained so that the width of each roller is 8 Newtons. (2) The carrier film 474 and the scale-forming resin spouted from the nip area , will tend to adhere to the patterned roller a, forming a sheet of the desired thickness until it is cured at a certain distance downstream of the slit. (3) The cured sheet and the carrier film can be removed from the patterned roller, and After receiving the tension under the controlled tension, the carrier film can be stripped from the formed pattern sheet at a certain distance downstream of the stripping point 4. The formed pattern sheet comprises the first layer 410a of the light guiding plate. The figure is a magnified view of the first layer 4, in which the pattern 252 is shown and not drawn to scale. The first layer of tick & has a thickness A, generally varying from 〇〇25 mm (mm) to 〇. 5 coffee. The preferred range is from about 〇.〇5mm to 〇35mm', and the preferred range is约15丽至〇.25mm. 异329 201219864 (4) The first layer 410a is then fed to a second extrusion station 47〇b having a second patterned roller 480b, and a second pressure roller 478b. - Layer 410a has a patterned side of pattern 252 that is rolled toward 478b toward the upper pressure and passed through a second unstitched area between rollers 480b and 478b while the second layer of resin 450b is squeezed by extruder 476b The sheet mold 477b is transferred to the unpatterned side of the first layer 410a. The pressure of the second nip area is controlled at P> the width of the roller per mm is 8 Newtons. The surface temperature of the patterned roller 48〇b is T2> Tg2-50 〇C' where Tg2 is the glass transition temperature of the second extruded resin 450b' and the temperature of the pressure roller 478b is ΤΡ2, ΚΤ2. The pattern 254 on the surface of the roller 48〇b is transferred from the roller 480b to the second lost seam. In the resin of the area. ^ (5) The resin 45〇b passing through the second nip zone will adhere to the first drawer 410a to form a composite optical sheet 3〇〇a. The composite optical sheet will be at a certain distance downstream of the second slit. Curing. Fig. 8C is an optical sheet 300a having a layer 41 (^ and 41牝) Larger image, wherein the patterns 252, 254 are shown, not drawn to scale. The layer 4l〇b has a thickness a, which can be changed from 〇. 卩 咖 咖 to 0. 5mm A 乂 乂 范围 范围 仍 仍 仍 仍 仍. 35mm, more preferably in the range of about 0. 15mm to 〇 · 25μμ. The total thickness of the optical sheet is 1 + is 2, the typical range is 0. 05mm to 1. 〇mm 'best range is from 〇丨 to 〇 · 7 5毫米至〇. (6) The cured optical sheet 300a is peeled off from the roller 480b and collected at a controlled tension of the charging station, and the sheet can be in-line (striped) or wrapped around the roller in the charging station. On 484a for later completion. The sheet contains a plurality of light guide plate patterns which must then be cut to the final specified length and width of the light guide plate designed in accordance with 16 95329 201219864. • The resin 450b extruded from the first extrusion station 470b is not necessarily the same as the resin 45〇a extruded at the first extrusion station 470a, and the thickness of the first layer and the second layer is not necessarily required to be The same (generally A妾仏), as long as the final thickness D and the optical properties of the composite panel meet the design requirements. The order in which the patterns 252 and 254 are applied is not necessarily sequential, and may be specified depending on implementation considerations. In one example, the molten resin 450a, 450b is polycarbonate (PC) having a glass transition temperature Tg of about 145 Å. In another example, the molten metal 450a, 450b is an impact modified PMMA having a glass transition temperature Tg ranging from 95 to 106C. Impact-modified PMMA is less brittle than pure pMMA, and 4 is easier to extrude than unmodified PMMA. In yet another example, the molten tree sorghum 450a 450b is a polyolefin-based polymer. The double-sided optical sheet 300a can also be prepared by a two-pass process at a single extrusion station. In particular, after the first layer of polymer resin 450a is squeezed into the crevices to allow the first layer of film to be prepared by the first patterned roller 480a, the first layer of film can be wound into a roll and stored for later use. . The first patterned roller 480a is then replaced by a second patterned roller 480b, and the first film roll is unrolled, passed back into the nip and patterned to the side of the pressure roller. The second layer of polymer resin 450b is The same extruder 476a and the extrusion core 477a are cast on the unpatterned side of the first layer to form the optical sheet 300a. Although this method requires only a single extrusion station, it is economically disadvantageous to pass the manufacturing procedure of the optical sheet 3〇〇a again. In some cases, the use of carrier film 474 to make the first layer is not desirable for those who are not in need of control, although film films made from carrier films are not used. More preferably, the extrusion casting method of the present invention, as shown in Fig. 9A, shows that the single-sided micropatterned layers 410a, 41Gb are tied to the two extrusion stations. Formed separately, similar to the fourth and fourth embodiments of the present invention. The two patterned layers 41a, 41〇b are formed in the layered factory layer forming station 490, and the unpatterned surfaces of the two layers are mutually abbreviated to form a single optical sheet 300b. The sides of the sheet are laminated at ~ and 254 as shown in Figure 9B. Similarly, the sheet contains a pattern of patterns, which must then be cut into a design light guide <=several light guides and widths. The final specified length of the two solid layers can be achieved in a variety of ways, including the 々 method, the pressure laminate method, the UV laminate method or the thermal laminate method. The solvent product = layer of the agent is applied to one or both of the surfaces to provide a thin layer of solution which is preferably applied to the unpatterned surface of the layer to promote adhesion. The excess solvent is then enthalpy, and the pressure build-up method is used to remove the pressure sensitive adhesion of the two surfaces. get on. In the UV lamination method, one or both of the films are contacted with an adhesive, and the adhesive can be promoted in the adhesive layer by the uv curing of the adhesive layer, and the temperature sensitive layer is applied to one or two surfaces. The upper and lower portions are just below the temperature of the light guide plate resin Tg, thereby promoting the adhesion between the layers without deforming the pattern layer. In all of the lamination processes (except for the solvent lamination process), the adhesive layer preferably has optical properties (especially refractive index, color and transparency) close to that of the light guiding plate resin to impart optical performance to the light guiding plate. % 图户斤 Impact minimization"Lamination and extrusion steps can be performed online, such as brother 18 95329

S 201219864 a shows, or proceeds offline, where the extrusion step is separated from the lamination step. The use of a carrier film in this manner is desirable, and the machine can be designed to produce the first layer and/or the second layer without the use of carrier film 474. Preferably, the extrusion casting method of the present invention is schematically shown in Fig. 10. The one-sided layer A having the pattern 254 is fabricated in a manner similar to the layer 410b shown in Figure 9A. Pattern 252 is then applied to the unpatterned side of layer 410b in a suitable printing process to form optical sheet 300c. For example, the one-sided layer 410b passes through a printing station 492 where the pattern 252 is printed on the unpatterned side of the film 410b. A variety of printing methods are available for this step, including inkjet printing, screen printing, and the like. In either case, the optical properties of the clear ink must carefully conform to the optical properties of the extruded layer. If the printed material is (ink) UV-sensitive, the UV station must be immediately after the printing station to cure the printed ink. The final optical sheet 300c has a total thickness which is nominally the same as the thickness of the layer 41 Ob, and the total thickness of the optical sheets 300a, 300b in the 8C and 9B drawings is much larger than the layer 410b. Optical sheet 300c, similar to optical sheets 300a and 300b, also contains a plurality of light guide plate patterns which must then be cut to a final specified length and width. The printing and extrusion steps can be performed on-line, as shown in Figure 10, or offline, with the printing step separated from the lamination step. The use of a carrier film in this method is desirable, and the machine can be designed to produce layer 410b without the use of carrier film 474. In contrast to other embodiments, this method requires less micromachining of patterned rollers, but the printing process may be limited by the shape and size of the discontinuous elements produced by this method. Preferably, the extrusion casting method of the present invention is schematically shown in Fig. 11A, 19 9S329 201219864. That is, the carrier film is a micropatterned ruthenium carrier film 474a. Polymer resin 450a is dispensed onto the patterned carrier film via extruder 476a and cross-web mold 477a. The carrier film and the read resin tend to adhere to the patterned roller 480a to form a sheet which is immediately entrained at a distance downstream of the nip. The cured sheet and the carrier film are <removed" on the patterned roller 48A and collected under controlled tension, and then the carrier film is stripped from the formed pattern sheet at a distance downstream of the stripping point 481a. As shown in Fig. 11B, 'the final optical sheet 30〇d has a pattern 254 transferred from the carrier film 474a on one surface, and the pattern 252 on the other surface is transferred from the patterning roller 480a. . The sheet contains a plurality of light guide plate patterns which must then be cut to the final specified length and width of the designed light guide plate. It is not necessary for the patterning roller 480a or 480b to engrave a pattern on the surface of the roller. Conversely, the pattern can be made from a patterned film wrapped on a roller, similar to the patterned carrier film 474a shown in the figures. In the present invention, if the carrier film is used to aid in forming the resin, it is conveyed through the nip zone through the stripping point, which must meet several key requirements: it must be hard and flexible, and it The high temperature and pressure of the nip area (where the hot melt is cast onto the carrier film) must maintain dimensional integrity and physical properties. In addition, the surface of the film must be very smooth and need to be adhered to the cured resin so that it can be easily peeled off from the formed patterned film at a point downstream of the stripping point. Examples of materials that meet these needs are not limited to, two-axis positioning (|;) 丨 丨 3117 〇 146] 1 " (: 6 (1) PET and PEN thin, poly hard film and poly vinegar (p 〇lyary lafe) film. 95329

S 201219864 Preferably, the extrusion casting method of the present invention is schematically shown in Fig. 12A. That is, the optical sheet 300e of the present invention is produced in a single patterning step by placing the pattern on both the patterning roller 480a and the pressure roller 480b without using a carrier film. Since the residence time of the resin and the patterned pressure roller 480b and the contact time are short in the nip area, it is preferable that the pattern transferred from the pressure roller 480b can be easily reproduced (for example, very shallow) to achieve the patterned sheet. Acceptable copy fidelity on both sides. In addition, by co-extruding a layer of a different resin having a more easily replicated and formed feature on the pressure roller side, a better replication can be achieved with a shorter contact time. A resin which can be used in this aspect is exemplified by a composition which is similar to a bulk polymer used in a light guide plate, but which has a lower molecular weight or a resin having a suitable plasticizer. In one example, the second optical sheet 300e has patterns 252 and 254 on its surface. This method is the easiest to achieve, but it is not optimal for quality and cost. Alternatively, Figure 12B provides a slightly modified method of Figures 12A and 11A. The extrusion casting method shown in Fig. 12B is the same as that shown in Fig. 12A except that the micro-patterned tape 479 transferred to the roller 478a is used instead of the patterned pressure roller 480b. Since the residence time of the resin and the belt 479 in the nip area and the contact time are short, it is preferred that the pattern transferred from the belt can be easily reproduced (e.g., very shallow) so as to be acceptable on both sides of the patterned sheet. Copy fidelity. The extrusion casting method shown in Fig. 12C is the same as that of Fig. 12B except that the patterning roller 480a is partially covered with a micropatterned tape 479 from the nip to the downstream of the nip. The optical sheet of the present invention is manufactured in a single patterning step by making a pattern on a surface from a pattern strip 479 and self-patterning the roller 48 on the opposite surface. A copy on a to get another pattern to achieve. The pattern strip 479 is wrapped around the pattern 牝 roller 480a by a length which increases the contact time of the resin with the strip 479, thereby increasing the copy fidelity of the feature transferred from the strip to the optical sheet. The extrusion casting process shown in Fig. 12D is similar to that shown in Fig. 12A except that the continuous micropatterned tapes 479a and 479b are wrapped around the drive rollers to replace the patterned rollers 480a, 480b. The final double-sided optical sheet 300e manufactured by the method embodiment shown in Figs. 12A to 12D has the same cross section as the optical sheet shown in Fig. 11B. The optical sheet 300e contains a plurality of light guide plate patterns which must thereafter be cut to the final specified length and width of the designed light guide plate. In all embodiments including patterned roll-to-roll, the surface temperature T' of the patterned roller is preferably greater than Tg_5 〇 ° C, more preferably greater than Tg -30 ° C, and particularly preferably greater than Tg-2 (TC, where Tg is Glass transition temperature of the extruded resin. The optical sheet produced by any of the above embodiments is finally transferred to a finishing station, wherein the sheet is cut into a plurality of double-sided light guide plates having a specified length of the designed light guide plate The width of the light guide plate made of a single optical sheet may have the same or different size and micropattern. Resin material Many polymer materials can be used to practice the invention. The resin material must be extrudable under typical extrusion conditions, easy to cast and The discontinuous and/or linear micropattern can be replicated. The material must also be sufficiently rigid and rigid to minimize cracking and changing of the shirt during actual use. In addition, the material must have two passes on visible light 95529 201219864 π. Transparency and low color. The most important factor in this application is the extinction coefficient. The extinction coefficient or the intrinsic optical density (0D) of a material can be obtained by the formula (10) I1.81.#) Count, which is a penetration + ^, [zeta] is the optical path length. This property must be as low as possible to minimize absorption losses in the light guide. Materials useful in the present invention include, but are not limited to, PMMA and other two acid polymers, including impact modifiers, and methyl methacrylates, and other acrylic and non-acrylic monomers. Copolymers, polycarbonates, polycycloolefins, cyclic block copolymers, polyamines, styrenics, polysulfones, polyesters, polyester-carbonates, and various miscible blends thereof. The p 0A i 0D value can vary from about 〇〇〇2/mni to 〇. 〇〇〇8/mm, while the typical range of polycarbonate is 〇. 〇〇〇3/mm to 〇. 〇〇 15/min, depending on the grade and purity of the material. EXAMPLES Inventive Example 1 The optical sheet 300 has a length center (four) loss of color, a width % β 343 ηηιη, and a thickness As ′ vary from 〇·1 mm to 〇. 7 mm. The optical sheet 300 has four light guide plate patterns, each of which has the same length, varies from 150 mm to 240 mm, and has a width ranging from 15 to 320 mm. Since all four light guide plates are fabricated in the same roller-to-roller process, the mother-light guide plate is manufactured at a machining line rate of 250 _i per second for 1 second. It can be understood that when using the same pattern roller on the same optical sheet 3〇〇 compared to a larger number of smaller light guides (e.g., length and width about 20 mm), each piece is in the same machining line rate. The manufacture of light guide plates s 23 95329 201219864 The production time will be even shorter. 5毫米变化。 The optical sheet 300 has a length of L w1436mm, a width of the heart of 686mm, and a thickness As can vary from 〇. lmm to 0. 7mm. The optical sheet 300 has 14 light guide plate patterns each having a length which varies from 150 mm to 240 mm and a width which can vary from 150 mm to 320 mm. The 14 light guide plate patterns have one or more of the following features. In one aspect, at least two of the 14 light guides have different widths. In another aspect, at least two of the 14 light guides have different widths. In still another aspect, at least one of the 14 light guide plates has the same width direction as the optical sheet 300. For example, the width direction of the light guiding plate 250a is as shown in Fig. 1 and is parallel to the width direction % of the optical sheet 300. In still another aspect, at least one of the 14 light guide plates has a width direction perpendicular to the optical sheet 300. For example, the width direction of the light guiding plate 250f is perpendicular to the width direction % of the optical sheet 300. In still another aspect, one of the plurality of light guiding plates, such as the width direction of the light guiding plate 250j, may be disposed at an angle of 0 to 90 degrees with respect to the width direction of the optical sheet 300. It is also possible that one or more of the light guide plates are not rectangular but are square, circular or other known shapes. Typically, since there is a blank space 260 between any two adjacent light guide plates, it is possible to increase the size of the light guide plate from the originally intended light guide plate by incorporating a portion of the blank space. Alternatively, the light guide can be cut to a smaller size than the original intended light guide. The advantage of optical sheets with different light guides is that light guides for different LCD applications can be fabricated in a single manufacturing step.

S 201219864 board. Due to the lack of sufficient display industry standards, different display users may require different sizes of light guides. The optical sheet 300 of the present invention provides a low cost solution to meet the diverse needs of multiple users. EMBODIMENT OF THE INVENTION Example 3 The optical sheet 300 has a length center "143611111, a width % «980 mm, and a thickness As, which can vary from 匪. 1匪 to 〇. 7mm. The optical sheet 300 has 21 light guide plate patterns each having a length which varies from 150 Å to 240 mm and a width which can vary from 150 mm to 320 mm. When the optical sheet 300 was manufactured at a machining rate of 152 mm/sec, it took about 9.4 seconds to manufacture an optical sheet 300 containing 21 light guide plates. The average manufacturing cost of a light guide plate is less than about 0.5 seconds, which is much higher than the practical injection molding method of a conventional light guide plate. Comparative Example For comparison, only a single light guide plate having a length or width greater than about 150 angstroms can be produced in a typical injection molding cycle. Therefore, the cycle time of each of the light guide plates is relatively long. Multiple light guide plates can be fabricated by injection molding at each cycle, but when both patterned surfaces are required to achieve good replication fidelity, the difficulty increases as the thickness decreases and the length and width of the light guide plate increases. To sum up, compared with the current general injection molding technology, the light guide plate having a length of at least 0.8 m and a width of at least 0.3 m and a large optical sheet can be used at a much higher rate and/or far. Larger size and smaller thickness. These light guides are also easily customizable to meet the changing needs of users s 25 95329 201219864. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a large optical sheet including a plurality of light guide plate patterns; FIGS. 2A and 2B are bottom and side views of a light guide plate cut by the large optical sheet of FIG. 1; 2C is a view showing a unit area used in definition of a density function of discontinuous elements patterned on one surface of the light guiding plate; FIG. 3A is an enlarged side view of the light guiding plate in a direction parallel to the width in the backlight unit; 3B is an enlarged side view of the light guide plate viewed in a direction parallel to the length; FIG. 3C is a top view of the linear 稜鏡 on the light guide plate; FIG. 3D is a top view of the curved wavy ridge on the light guide plate; 4A-1, 4A-2 and 4A-3 show perspective, top and side views of the first type of discontinuous elements; Figures 4B-1, 4B-2 and 4B-3 show perspectives of the second type of discontinuous elements , top view and side view; Figures 4C-1, 4C-2 and 4C-3 show perspective, top and side views of the third type of discontinuous elements; Figures 5A and 5B are patterns containing multiple sub-patterns, respectively Front view and expanded view of the scroll wheel; Figures 6A and 6B are included Patterned scroll wheel front view and unfolded view; 26 95329 201219864 Figures 7A and 7B show the same light guide plate cut from the use of the 5A-6B _ a optical sheet; The apparatus and method of the optical sheet of the present invention are shown in Figs. 8B and 8C as the final optical thinness of the pattern 盥 左 左 & & m m m m m ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ A schematic diagram of an apparatus and method for inventing an optical sheet; ~ Figure 9 is a schematic diagram of the final optical thin surface manufactured by the method of Figure 9; Figure 10 is a schematic diagram of the apparatus and method for fabricating the optical sheet of the present invention. FIG. 11B is a schematic diagram showing a final optical cross section manufactured by the method of FIG. 11A; FIG. 12A is a device and a square diagram for manufacturing the optical sheet of the present invention; and FIG. 12B, 12C The 12D diagram is a schematic diagram of three variations of Figure 12A of the present invention.丄 [Main component symbol description] 12 Light source 14 , , , ,; End surface, 15b side surface 16 ^ Output surface

S 95329 27 201219864 17 18 22 142 216 217 227, 227a, 227b, 227c 250a, 250b, 250c, 250d, 250i, 250j 250, 250al, 250a2 252, 254 252a, 252b, 252c, 252d 260 300, 300', 300a, 300b, 410a, 410b 450a, 450b 470a, 470b 472a 474 474a 476a, 476b 477a, 477b 478a, 478b 479, 479a, 479b bottom surface input surface turning film reflective film 微 (micro) pattern discontinuous elements 250e, 250f , 250g, 250h, light guide plate pattern light guide plate pattern sub-pattern blank space 300c, 300d, 300e optical sheet (one-side micro-pattern) layer resin extrusion station supply roller carrier film patterned carrier film extruder extrusion die (pressure) Roller patterned belt 28 95329 201219864 480a, 480b patterned roller 481a stripping point 484a roller 490 stacking station 492 printing station Ds, Lh, D2 thickness Z ' Δ Z ' Δ Z〇' Z/o ' Zi ' X2 , Ln, La:, Lb, Le, Li, L% L\q, Ln, Ln, Ls, Ln, Lr2 length w, δ iv, λ m >, m, m, W2- - Wi m > m〇' Wpi ^ Wp2^ ws Width 0 Origin «1 ' flz ' <23 ' (34 ' <35 ' «6 area a 〇 apex angle d south degree R\ ' R2 roller radius Wjn, Wr2 roller width Ιλ, 叭, 29 95329

Claims (1)

201219864 VII. The scope of the patent application: 1. The optical sheets of a plurality of light guide plates each having a micro-patterned output surface for light and a micro-patterned bottom surface of the output table 2 The system comprises: a mesh, a pinch between the first pressure roller and the first image=the wheel, and a first layer formed on the surface of the first pattern wheel and the clamping force ρι, the first layer Having an unpatterned surface: a surface and a patterned surface having a micropattern transferred from the first patterned roller and transferring the first layer to a second patterned roller in the second extrusion station a gap between the two rollers; and squeezing the second resin into the unpatterned watch on the second layer of the dust wheel and the second patterned roller Forming a second layer on the second patterned roller surface temperature T2 and the second quilted cover, Ρ2, the second layer having a micropattern transferred from the second patterned = wheel, the first layer and the second layer of the combination The layer forms the optical sheet containing the plurality of light guide plate patterns. 2. 4. For the optical sheet described in (4), the length of the optical sheet of the towel is greater than or equal to 〇. 8m. The optical sheet of claim 4, wherein the optical sheet has a width % greater than or equal to 0.3 m. The optical sheet of claim 1, wherein the optical sheet has a thickness Ay ranging from 〇5 mm to about 2 mm. The optical sheet of claim 1, wherein the light guide 95329 5. 201219864 has a width and length greater than or equal to 〇. 15m. 6. The optical sheet of claim 2, wherein the micropattern on the output or bottom surface comprises discontinuous elements, and the micropattern on the other major surface comprises continuous elements. 7. The optical sheet of claim 2, wherein the micropattern on both the output surface and the bottom surface comprises a continuous element. The optical sheet of claim 1, wherein the micropattern on both the output surface and the bottom surface comprises discontinuous elements. 9. The optical sheet of claim 7, wherein the discontinuous element has a length and width greater than or equal to 15/zm and a height less than = equal to 12 /z m. The optical sheet of claim 7, wherein the discontinuous element has a length Δ£, a width Δ酽, and a height d, and the ratio of d/ Δ酽 is less than or equal to 〇.45. U. The optical sheet of claim 2, wherein τι is greater than Tg2 (TC, and T2 is greater than Tg2-5 (rc, wherein Tgi and butyl are respectively the first resin and the second resin) The optical sheet of claim i, wherein the squeezing pressures P1 and P2 are greater than 8 Newtons per millimeter of the roller width. 13· The optical sheet of claim i, Wherein the first layer is extruded onto the seam and the strip is peeled off. The optical sheet of claim 1 wherein one of the first and second patterned rollers or The pattern on both is provided by the patterned tape. C 95329 201219864 15.== The first learning sheet described in item 】, (4) a tree ^ The second resin is polycarbonate, thin tobacco polymer Or an acrylic polymer. 16. The optical sheet of claim 1 and the second resin phase 1 wherein the first tree is the same. 95329 S